The Impact of Cruciferous Vegetable and Soy Phytochemicals on Prostate Cancer Cell Progression

Background: Prostate cancer is a disease of aging, particularly in nations of affluence, with risk increasing several hundred-fold from age 40 to 75. Indeed, as one of the most common malignancies in Americans, it is a significant health care burden. In addition, prostate cancer treatment strategies result in significant negative impacts on quality of life for a growing number of senior citizens. Therefore, prevention strategies are critically needed. Accumulating research suggests that several dietary factors may reduce risk, such as consumption of cruciferous vegetables, soy, and tomatoes. Our laboratory work and others suggests that specific components of these foods demonstrate anticancer properties, such as inhibition of cancer cell proliferation and enhanced sensitivity to activation of cell death programs (apoptosis). Objective: We hypothesize that bioactive phytochemicals can be combined in specific combinations within carefully designed functional foods that meaningfully contribute to the prevention of prostate cancer progression. We evaluated the combined effects of the bioactive components in arugula in cell-based studies, using erucin, sulphoraphane and genistein. Design: Prostate cancer cells (PC3) were treated in vitro with 5-20 uM of sulforaphane, 5-20 uM of erucin, and 5-40 uM of genistein, alone and in specific combinations. Cell viability was measured at 24, 48 and 72 hours after treatment using the Sulforhodamine B method to investigate the combined contribution of proliferation and apoptosis. In addition, preliminary cell cycle analysis by flow cytometry was conducted to determine the impact of erucin and genistein alone and in combination on cell cycle progression. Results: Cruciferous vegetables components at 20 uM such as sulforaphane (high in broccoli) and erucin (high in arugula) were equally effective at 72 hours with 75% vs 80% viability respectively. Genistein (20 uM) from soy foods was also modestly effective, reducing viability by 35%. Erucin and genistein display unique time and dose dependent profiles of inhibition. Significance: Laboratory in vitro studies may help us define combinations of phytochemicals that have combined anticancer effects, helping us to design novel food products (e.g. a vegetable juice) for future human studies.No embarg